1. Field of the Invention
The present invention relates to a liquid dispensing apparatus for automatically opening a lid of a container to draw liquid from within a container and then dispense the liquid, and more particularly to an automatic analyzing apparatus provided with such a liquid dispensing apparatus.
2. Description of the Related Art
It is generally performed to prepare and analyze a sample by dispensing specimens such as blood serum and blood plasma and test reagents such as reaction agents and diluents, which are contained in containers, with a liquid dispensing apparatus such as a dispensing pipette after drawing from them. Particularly, in tests such as a blood coagulation test and an immunoassay, there are used automatic analyzers dispensing a plurality of specimens and test reagents successively and analyzing the reaction thereof. These automatic analyzers are different in the timing of replacement of their reagents since the amount of reagents consumed and the number of tests requested vary greatly in each analyzing item. Further, some analyzers require much time from the start to the end of analyses due to setting many specimen containers and analyzing many items. Therefore, the analyzer may be used in a state in which test reagent containers and specimen containers are left set at these analyzers for a long period of time.
Thus, when reagent containers and specimen containers are left set at these analyzers for a long period of time, evaporation/drying and mixing of dust cause deterioration of reagents or contamination of specimens and adversely affect the results of the analysis. So, to enhance the stability in storage, an opening of a container has been reduced in size or a container holding part has been kept cool. However, it is difficult to prevent the deterioration of reagents and specimens by only these means.
Consequently, there are presented an apparatus provided with a mechanism for automatically closing an opening of a reagent container with a lid except when drawing a reagent to prevent the deterioration of the reagent.
(a) Automatic analyzers which are provided with a mechanism section including a member corresponding to an opening of a reagent container and has a function of blocking an opening of a reagent container by operating the mechanism section automatically are disclosed in Japanese Unexamined Utility Model Publication No. Sho 57(1982)-185964, Japanese Unexamined Patent Publication No. Hei 8(1996)-160050 and Japanese Unexamined Patent Publication No. Hei 10(1998)-311835.
(b) In Japanese Unexamined Patent Publication Nos. Sho 64(1989)-61667 and Hei 8(1996)-94624, there are disclosed automatic analyzers, which a container to which a lid is connected is used in as a reagent container and a rotation mechanism with a member catching the lid is provided at, having a function of pulling and opening the lid of the reagent container by rotating the rotation mechanism.
In the apparatus of a conventional type described in above group (a), the mechanism part for blocking the opening of the container has to be configured to correspond to the container and therefore the constitution of the apparatus subjects to constraints. And, when reagents adhere to the member blocking the opening, contamination of a reagent to be used next may arise. Further, since the container and the lid are separated, it is required to attach and detach the lid before and after measuring and to preserve the lid at another location during measuring, and therefore it requires manpower.
In the apparatus of a conventional type described in the above group (b), to solve this problem, a lid is coupled to a reagent container. However, the automatic analyzer requires the rotation mechanism and a driving mechanism for letting the rotation mechanism catch the lid of the reagent container. Therefore, the constitution and operational controls of these mechanisms becomes complicated, and incorporating such complex mechanisms particularly into the automatic analyzer causes upsizing of the apparatus and lowering of the speed of the treatment due to the complexity of operational controls. Furthermore, since the lid of the reagent container needs to be configured to retain a state of the lid of the reagent container opened after being opened by the rotation mechanism, the constitution is limited.
It is an object of the present invention to provide a liquid dispensing apparatus which allows a lid of a container to be opened and closed with a simple constitution and control. And it is also an object of the present invention to provide a liquid dispensing apparatus being capable of using a container having a high degree of flexibility in a structure with respect to a container to be used.
It is another and further object of the present invention to provide an automatic analyzing apparatus provided with such a liquid dispensing apparatus.
In accordance with the present invention, there is provided a liquid dispensing apparatus, including a container for containing a liquid; a container setting part for setting the container; and a dispensing mechanism part having a pipette for drawing and dispensing the liquid, a raising/lowering part for raising and lowering the pipette, a base for holding the raising/lowering part and a base driving part for moving the base, thereby enabling to act the pipette at a suitable position, wherein a lid being capable of being opened/closed with an opening/closing pivot part is coupled to the container, and the lid is provided with a hook part projecting upward for engaging, and the base is provided with a projection part for engaging, which opens the lid by abutting against the hook part and moving the hook part toward the pivot part side of the container as the base moves relatively to the container and retains the state of the lid opened.
In such a liquid dispensing apparatus, it becomes possible to open the lid and to retain the state of the lid opened during drawing/dispensing of the pipette through the relatively simple structural addition of providing the conventional lid with the hook part and the conventional base with the projection part.
Furthermore, an automatic analyzing apparatus of the invention may include the liquid dispensing apparatus described above.